Tag Archives: CMGC

UDOT is moving to an all-3D environment which includes greater use of available design capabilities and an eventual move to a full 3D project workflow.

A photo-realistic image: UDOT built a new bridge over the Virgin River on S.R. 9 near Hurricane to accommodate increased traffic volume. This rendered image shows the new bridge superimposed over the existing bridge, which remains in use.

Embracing a 3D workflow environment will produce some important advantages, including the use of models that can be viewed from all angles in order to assess constructability, utility clash detection models that show a full representation of underground utilities, and animations that can show the built project along with expected traffic flow.

3D models, animations and illustrations can help bridge the communication gaps that sometimes occur among specialties at UDOT, or between the agency and stakeholder groups, since complex engineering data is more easily understood when presented in 3D.

For UDOT designers, the move to 3D represents “a fine tuning of the way we design,” says Bob Peterson, UDOT Methods Engineer. “We’ll be taking our 3D design to a full completion instead of just doing a paper copy as the final output.”

A full 3D workflow

Moving to a full 3D workflow means that projects will be modeled and provided to contractors as a 3D engineered model at advertising, and contractors will return an as-built 3D model that accurately represents project outcome.

Designers at UDOT have been working in 3D for about 20 years. Currently, when projects are advertised, 2D plan sets are made available to all bidding contractors. During the advertising time frame, contractors take those 2D sets and may create their own 3D model. Once the project is awarded, the winning contractor will typically finish a 3D model or hand-enter information for Automated Machine Guidance.

Getting as-built 3D models will represent a big efficiency boost to UDOT. “Once we get to the point where we know exactly what the existing condition is, then the designers don’t have to start from scratch anymore,” explains George Lukes, Standards Design Engineer.

Challenges and strengths

Lukes is overseeing the effort to move to a full 3D workflow. He sees challenges ahead, but recognizes that UDOT has some advantages as an agency, including working with a willing and capable consulting and contracting community.

“The big deal is advertising the project with the model as the legal document,” says Lukes. “Right now the legal documents are our plan sheets, the paper copies – legally that’s what the contractor has to follow. It’s a huge challenge to give the model to the contractor and say ‘this now is the legal document,’ but I think our contractors and consultants are very willing to sit down and figure a way to make that work.”

UDOT Region Four will take on the initial challenge of delivering a 3D model as an advertising package for three projects. All three projects will use CMGC, an innovative contracting method that allows close collaboration between UDOT and a contractor in the preconstruction phase.

Collaboration with the contractor during design will help UDOT minimize risks encountered when building the project “because they know the construction risks better than we do,” says Lukes. “It’s going to give us information that we need, the contractor will be on board with us while we do it, and hopefully we’ll get a lot of good lessons learned from that too.”

Fully embracing 3D capabilities will produce comprehensive planning, construction and design solutions that will benefit UDOT and all contract partners and road users. UDOT will learn how to better minimize risk. Bidding contractors will realize a big efficiency by not having to create baseline models from scratch. The winning contractor will also have UDOT’s model to modify for construction and 3D as-builts will make subsequent design processes more efficient. The outcome will be better roads and a more efficient use of transportation funding.

In recent years UDOT has been able to implement innovative bridge building techniques but do you know what the impetus for this was? It started with innovative contracting. By utilizing these types of contracts we are able to involve the construction industry earlier for more efficient delivery of our projects.

The Colorado River Bridge project was completed using DBB. A specialty designer was hired and then also contracted to assist with inspection during construction.

We use three basic contract types: design-bid-build (DBB), design-build (DB) and construction manager/general contractor (CMGC). Each has its own benefits and risks and UDOT project managers, in coordination with UDOT senior leaders, determine early on what type of contract will meet the needs of their project and ultimately provide the best product (aka road, bridge, etc.).

Design-Bid-Build

DBB is our traditional method of contracting and is the most familiar to everyone. With these contracts a designer completes their part of the process before a construction contractor is involved. Basically, the name explains it all: first the design is completed, then it is put out for bid and finally a contractor is selected to build the project. The majority of our projects use this type of contract.

It was determined that we could get a better price using DB on the Geneva Road project by allowing the contractor to propose the most efficient design while maximizing the available funding.

Design-Build

DB came about as a result of the 2002 Winter Olympics. The executive director at the time was Tom Warne and I-15 needed to be improved through Salt Lake County to meet the increased demands the Olympics would put on the highway. To meet the tight timeline Mr. Warne worked with legislators to allow UDOT to use a new method of contracting, design-build.

DB contracts allow for the design and construction to be completed under one contract. The contractor actually manages the design and construction, and is involved from the beginning. This means the company that will be building the project is part of the discussion as elements of the project are designed. Because of this early contractor involvement, the time frame for a project is greatly reduced. Contractor involvement is also what has brought about innovations such as bridge moves; who better to bring new ideas to the table than the one who will be putting them into practice.

A landslide took out S.R. 14 and made it impassable. In order to have the most innovative design, and to get construction started right away, CMGC was selected. This also allowed us to develop a design utilizing equipment the contractor proposed.

Construction Manager/General Contractor

CMGC is somewhat similar to DB in that it also shortens the timeline between design and construction and allows for innovation since the contractor is involved from the beginning. The difference is that the contractor is involved during the design process as part of a team managed by UDOT, working alongside a design consultant. Another difference is that while the contractor may continue on past design into construction, if they meet all of the requirements, we also reserve the right to sever the contract once the design is complete making it a design-bid-build.

CMGC allows us to use some of the positive elements from both DBB and DB. The idea for this came from the building industry and we saw it used on a transportation project by the city of Phoenix, Arizona in 2004. Following the success of DB we wanted to include another innovative contracting method.

In the end our goal is to provide our project managers with options so that they can build the best project possible. These innovative contracting methods allow them to select a delivery process that keeps low bid in the forefront, but that also allows for new ideas and practices to emerge.

Note from author: Special thanks to Michelle Page, Project Controls and Innovative Contracting Engineer, and Michael Butler, Contract Administrator, for their help with this post.